Search found 819 matches

by eslapion
Sun Oct 20, 2019 3:51 pm
Forum: For Sale
Topic: GandALF, sub for 1541 custom IC MOS 325572-01
Replies: 14
Views: 2793

Re: GandALF, sub for 1541 custom IC MOS 325572-01

Price dropped to 18 Euros or 20$US.
by eslapion
Sun Oct 20, 2019 10:37 am
Forum: For Sale
Topic: SaRuMan-64 C64 static RAM for DRAM replacement board
Replies: 2
Views: 275

Re: SaRuMan-64 C64 static RAM for DRAM replacement board

Ray Carlsen has used on of my modules to replace all 8 DRAM ICs on an older board 250407.
P1010180.JPG
The 8 DRAM chips needed about 240mA of power in all. The single module now uses less than 5mA.
by eslapion
Sat Oct 19, 2019 7:29 pm
Forum: For Sale
Topic: SaRuMan-TED 64k RAM for C16 and C116
Replies: 2
Views: 9

SaRuMan-TED 64k RAM for C16 and C116

I am now offering a new type of 64k RAM expansion for the C16 and C116. This type of expansion installs under the TED and is extremely compact. It uses modern static RAM which uses a trickle amount of power. It uses special thin pins adapted to the peculiar (as in dirt cheap...) 48 pins socket inst...
by eslapion
Sat Oct 19, 2019 3:47 pm
Forum: Hardware
Topic: 1541C unusual "Shorter Board" version - J3?
Replies: 12
Views: 42

Re: 1541C unusual "Shorter Board" version - J3?

... The wire didn't fail at any of the bond points to the terminals, but down in the coil winding somewhere. I read somewhere that it is suspected the heads weren't sealed properly. Well - that's kind of true in that the bond points of the windings to the PCB are not potted in the silicone, so they...
by eslapion
Fri Oct 18, 2019 3:13 pm
Forum: Hardware
Topic: 1541C unusual "Shorter Board" version - J3?
Replies: 12
Views: 42

Re: 1541C unusual "Shorter Board" version - J3?

I just noted a problem with the 1541C. If you use the very short board, every time you turn on the drive, it will knock the stepper motor down the track 0 stop (like formatting does) even with the presence of a track 0 sensor. Guaranteed drive misalignment just by turning the drive off and on... Ano...
by eslapion
Fri Oct 18, 2019 5:25 am
Forum: Hardware
Topic: 1541C unusual "Shorter Board" version - J3?
Replies: 12
Views: 42

Re: 1541C unusual "Shorter Board" version - J3?

So out of all the 1541 drives which is the easiest to work on from your perspective? I have an original 1541 that is marked VIC-1540 on the rear and the board is 1540 full length. Tons of discrete logic chips on this board. From a trouble-shooting perspective I guess this could be good, since repla...
by eslapion
Wed Oct 16, 2019 8:17 pm
Forum: Hardware
Topic: The Dos and Don'ts of using an EPROM as PLA in a C64.
Replies: 90
Views: 3477

Re: The Dos and Don'ts of using an EPROM as PLA in a C64.

I am not too sure if the numbers I am getting are because the test equipment is out or the C64 is out.. All the C64''s I am testing are PAL versions.... Looks perfectly ok to me. You've tapped into the CPU clock which is a nice square wave. The minimum, accounting for the 10X probe not recognized b...
by eslapion
Wed Oct 16, 2019 8:07 pm
Forum: Hardware
Topic: 1541C unusual "Shorter Board" version - J3?
Replies: 12
Views: 42

Re: 1541C unusual "Shorter Board" version - J3?

If so, I found one document that says it's a generic H36A2U57 of which there seem to be small surplus repositories here and there. There is absolutely nothing generic about that component. The number printed on it is sometimes different. See: https://www.nightfallcrew.com/wp-content/gallery/commodo...